You receive a presentation marriage certificate on the day and this is included in the cost.
However, I also recommend that you obtain a certificate of marriage as many government authorities do not accept the presentation certificate as evidence of marriage. In Queensland, the certificate currently costs $37.00 and is issued by Births, Deaths and Marriages after they receive your application. If you would like a commemorative certificate, this is issued with the standard certificate as well and will cost $50.00.
If you complete the appropriate form with me and pay the fee at the same time as the fee for the ceremony, I will forward the application together with the official paperwork. This means that you do not need to wait longer than necessary for the certificate, or supply extra proof of identity to Births, Deaths and Marriages in Queensland.